docs: def parse_reference(reference):
      """
      parse provided image reference into <image_repository>:<tag>
  
      :param reference: str, e.g. (registry.fedoraproject.org/fedora:27)
      :return: collection (tuple or list), ("registry.fedoraproject.org/fedora", "27")
      """
      if ":" in reference:
          im, tag = reference.rsplit(":", 1)
          if "/" in tag:
              # this is case when there is port in the registry URI
              return (reference, "latest")
          else:
              return (im, tag)
  
      else:
          return (reference, "latest")